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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | LINKING | SEE ALSO | COLOPHON |
KEYCTL_PKEY_QUERY(3) Linux Key Management Calls KEYCTL_PKEY_QUERY(3)
keyctl_pkey_query - Query public key parameters
#include <keyutils.h>
long keyctl_pkey_query(key_serial_t key, const char *info,
struct keyctl_pkey_query *result);
keyctl_pkey_query() queries the public key parameters associated with
a kernel key that supports these operations (typically asymmetric-
type). The caller must have search permission on the target key to
be able to query its parameters.
When invoking the function, key indicates the key to be queried, info
points to a space- or tab-separated string of "key[=value]"
parameters and result points to a buffer in which the result will be
placed.
The parameters that can be used in the info parameter string are
dependent on the type of key. Parameters can specify such things as
encoding types (such as "enc=pkcs1"); see asymmetric-key(7) for more
information.
If successful, the result is written into the following struct:
struct keyctl_pkey_query {
unsigned int supported_ops;
unsigned int key_size;
unsigned short max_data_size;
unsigned short max_sig_size;
unsigned short max_enc_size;
unsigned short max_dec_size;
};
The supported_ops field contains a bitmask of the following con‐
stants:
KEYCTL_SUPPORTS_ENCRYPT
KEYCTL_SUPPORTS_DECRYPT
KEYCTL_SUPPORTS_SIGN
KEYCTL_SUPPORTS_VERIFY
indicating what operations are supported and thus which of the other
keyctl_pkey_*() operations can be used with this key.
The key_size field indicates the number of bits in the key size and
the max_data_size, max_sig_size, max_enc_size and max_dec_size fields
indicate the maximum sizes in bytes of a blob of data to be signed, a
signature blob, a blob to be encrypted and a blob to be decrypted
respectively.
On success keyctl_pkey_query() returns 0. On error, the value -1
will be returned and errno will have been set to an appropriate
error.
ENOKEY The key specified is invalid.
EKEYEXPIRED
The key specified has expired.
EKEYREVOKED
The key specified has been revoked.
EACCES The key exists, but is not searchable by the calling process.
ENOPKG Some facility needed to complete the requested operation is
not available. This is most probably a requested or required
digest or encryption algorithm.
EFAULT Bad address.
This is a library function that can be found in libkeyutils. When
linking, -lkeyutils should be specified to the linker.
keyctl(1), add_key(2), keyctl(2), keyctl(3), keyctl_pkey_encrypt(3),
keyctl_pkey_sign(3), asymmetric-key(7), keyrings(7), keyutils(7)
This page is part of the keyutils (key management utilities) project.
Information about the project can be found at [unknown -- if you
know, please contact man-pages@man7.org] If you have a bug report for
this manual page, send it to keyrings@linux-nfs.org. This page was
obtained from the project's upstream Git repository
⟨http://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git⟩
on 2020-08-13. (At that time, the date of the most recent commit
that was found in the repository was 2020-07-07.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
Linux 8 Nov 2018 KEYCTL_PKEY_QUERY(3)
Pages that refer to this page: keyctl(3) , keyctl_pkey_decrypt(3) , keyctl_pkey_encrypt(3) , keyctl_pkey_sign(3) , keyctl_pkey_verify(3) , asymmetric(7) , asymmetric-key(7)